Segment::getFirstContactSetId

protected function getFirstContactSetId()
{
	foreach ($this->data['ENDPOINTS'] as $endpoint)
	{
		if ($endpoint['MODULE_ID'] !== 'sender' || $endpoint['CODE'] !== 'contact_list')
		{
			continue;
		}

		if (empty($endpoint['FIELDS']['LIST_ID']))
		{
			continue;
		}

		return $endpoint['FIELDS']['LIST_ID'];
	}

	return null;
}